/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
 * in the United States and other countries.]
 *
 * --------------
 * TickUnits.java
 * --------------
 * (C) Copyright 2001-2008, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes
 * -------
 * 23-Nov-2001 : Version 1 (DG);
 * 18-Feb-2002 : Fixed bug in getNearestTickUnit (thanks to Mario Inchiosa for
 *               reporting this, SourceForge bug id 518073) (DG);
 * 25-Feb-2002 : Moved createStandardTickUnits() method from NumberAxis, and
 *               added createIntegerTickUnits() method (DG);
 * 01-May-2002 : Updated for changes to the TickUnit class (DG);
 * 18-Sep-2002 : Added standardTickUnit methods which take a Locale
 *               instance (AS);
 * 26-Sep-2002 : Fixed errors reported by Checkstyle (DG);
 * 08-Nov-2002 : Moved to new package com.jrefinery.chart.axis (DG);
 * 26-Mar-2003 : Implemented Serializable (DG);
 * 13-Aug-2003 : Implemented Cloneable (DG);
 * 23-Sep-2003 : Implemented TickUnitSource interface (DG);
 * 03-Dec-2003 : Adding null values now throws exceptions (TM);
 * 11-Jan-2005 : Removed deprecated methods in preparation for 1.0.0
 *               release (DG);
 *
 */

package net.droidsolutions.droidcharts.core.axis;

import java.io.Serializable;
import java.text.NumberFormat;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 * A collection of tick units, used by the {@link DateAxis} and
 * {@link NumberAxis} classes.
 */
public class TickUnits implements TickUnitSource, Cloneable, Serializable {

	/** For serialization. */
	private static final long serialVersionUID = 1134174035901467545L;

	/** Storage for the tick units. */
	private List tickUnits;

	/**
	 * Constructs a new collection of tick units.
	 */
	public TickUnits() {
		this.tickUnits = new ArrayList();
	}

	/**
	 * Adds a tick unit to the collection. The tick units are maintained in
	 * ascending order.
	 * 
	 * @param unit
	 *            the tick unit to add (<code>null</code> not permitted).
	 */
	public void add(TickUnit unit) {
		if (unit == null) {
			throw new NullPointerException("Null 'unit' argument.");
		}
		this.tickUnits.add(unit);
		Collections.sort(this.tickUnits);
	}

	/**
	 * Returns the number of tick units in this collection.
	 * <P>
	 * This method is required for the XML writer.
	 * 
	 * @return The number of units in this collection.
	 */
	public int size() {
		return this.tickUnits.size();
	}

	/**
	 * Returns the tickunit on the given position.
	 * <P>
	 * This method is required for the XML writer.
	 * 
	 * @param pos
	 *            the position in the list.
	 * 
	 * @return The tickunit.
	 */
	public TickUnit get(int pos) {
		return (TickUnit) this.tickUnits.get(pos);
	}

	/**
	 * Returns a tick unit that is larger than the supplied unit.
	 * 
	 * @param unit
	 *            the unit.
	 * 
	 * @return A tick unit that is larger than the supplied unit.
	 */
	public TickUnit getLargerTickUnit(TickUnit unit) {

		int index = Collections.binarySearch(this.tickUnits, unit);
		if (index >= 0) {
			index = index + 1;
		} else {
			index = -index;
		}

		return (TickUnit) this.tickUnits.get(Math.min(index, this.tickUnits
				.size() - 1));

	}

	/**
	 * Returns the tick unit in the collection that is greater than or equal to
	 * (in size) the specified unit.
	 * 
	 * @param unit
	 *            the unit.
	 * 
	 * @return A unit from the collection.
	 */
	public TickUnit getCeilingTickUnit(TickUnit unit) {

		int index = Collections.binarySearch(this.tickUnits, unit);
		if (index >= 0) {
			return (TickUnit) this.tickUnits.get(index);
		} else {
			index = -(index + 1);
			return (TickUnit) this.tickUnits.get(Math.min(index, this.tickUnits
					.size() - 1));
		}

	}

	/**
	 * Returns the tick unit in the collection that is greater than or equal to
	 * the specified size.
	 * 
	 * @param size
	 *            the size.
	 * 
	 * @return A unit from the collection.
	 */
	public TickUnit getCeilingTickUnit(double size) {
		return getCeilingTickUnit(new NumberTickUnit(size, NumberFormat
				.getInstance()));
	}

	/**
	 * Returns a clone of the collection.
	 * 
	 * @return A clone.
	 * 
	 * @throws CloneNotSupportedException
	 *             if an item in the collection does not support cloning.
	 */
	public Object clone() throws CloneNotSupportedException {
		TickUnits clone = (TickUnits) super.clone();
		clone.tickUnits = new java.util.ArrayList(this.tickUnits);
		return clone;
	}

	/**
	 * Tests an object for equality with this instance.
	 * 
	 * @param obj
	 *            the object to test (<code>null</code> permitted).
	 * 
	 * @return A boolean.
	 */
	public boolean equals(Object obj) {
		if (obj == this) {
			return true;
		}
		if (!(obj instanceof TickUnits)) {
			return false;
		}
		TickUnits that = (TickUnits) obj;
		return that.tickUnits.equals(this.tickUnits);
	}

}
